Re: CommsTime times?

["B.M. Cook" <b.m.cook@xxxxxxxxxxxxxx>]

Roger et al.,

> > >   6. With the PAR version of delta, the communication loads are the same
> > 
> > In the hardware case, with the optimisations reported at CPA2000, the
> > reverse is the case. A 2-component PAR is FASTER than a 2-component SEQ.
> > At best, if both communications are ready to proceed, PAR is twice as fast
> > as SEQ.

> Don't forget, however, that Peter's commstime benchmark program runs
> just one value around the cycle of three processes.  Thus, there are
> not enough potential communications at any instant to keep truly
> parallel hardware fully busy - on FPGA we are not time-sharing a common
> processor as in the other implementations being discussed.

In the specific case of the Delta function there is no problem, values leave
to go around the loop and to the sink/timing process - both of which are
able to accept data and allow a doubling of speed for PAR.

I agree that doubling the speed of one part doesn't double the speed of the
whole benchmark.

	      Barry.